No abstract available.
Elasticity Imaging Techniques ; Elasticity ; Tendons ; Ultrasonography

No abstract available.
Elasticity Imaging Techniques ; Pancreatic Neoplasms

Developing an acoustic radiation force excitation module including 64 channels based in FPGA for ultrasound elastography. The circuit of the module was derived in bipolar, and the parameters such as excitation frequency, pulse repetition frequency, pulse number, element number and focus depth were adjustable. The acoustic field for special parameter was experimented with OptiSon laser acoustic field system with a result which reflects the width of focal spot is about 3 mm. The acoustic power was experimented with RFB2000 radiation force balance with a result which reflects acoustic power is increasing linearly with the number of pulses and the number of elements, and is increasing squarely with the peak-to-peak value of excitation voltage. The module is promising in factual application which can be triggered externally in synchronously, and can be combined with B-mode ultrasound system for ultrasound elastography.
Acoustics ; Elasticity Imaging Techniques ; Ultrasonics

Elastography is an imaging modality for the evaluation of tissue stiffness, which has been used for the analysis of superficial organs, such as those of the breast and prostate. The measurement of tissue elasticity has been reported to be useful for the diagnosis and differentiation of tumors, which are stiffer than normal tissues. Endoscopic ultrasonography elastography (EUS-EG) is a promising imaging technique with a high accuracy for the differential diagnosis of solid pancreatic tumors. However, to date EUS-EG has not been used to provide complementary information for biologic behavior of adenxal mass. We report our experience of EUS-EG in a patient with adnexal mass.
Breast ; Diagnosis, Differential ; Elasticity ; Elasticity Imaging Techniques ; Endosonography ; Humans ; Prostate

The most troublesome of ultrasonic B-mode imaging is the difficulty of accurately diagnosing cancers, benign tumors, and cysts because they appear similar to each other in B-mode images. The human soft tissue has different physical characteristics of ultrasound depending on whether it is normal or not. In particular, cancers in soft tissue tend to be harder than the surrounding tissue. Thus, ultrasound elasticity imaging can be advantageously used to detect cancers. To measure elasticity, a mechanical force is applied to a region of interest, and the degree of deformation measured is rendered as an image. Depending on the method of applying stress and measuring strain, different elasticity imaging modalities have been reported, including strain imaging, sonoelastography, vibro-acoustography, transient elastography, acoustic radiation force impulse imaging, supersonic imaging, and strain-rate imaging. In this paper, we introduce various elasticity imaging methods and explore their technical principles and characteristics.
Elasticity Imaging Techniques ; Elasticity* ; Humans ; Methods ; Ultrasonics ; Ultrasonography*

PURPOSE: This study was conducted to determine the influence of standoff material on acoustic radiation force impulse (ARFI) measurements in an elasticity phantom by using two different probes. METHODS: Using ARFI elastography, 10 observers measured the shear wave velocity (SWV, m/sec) in different lesions of an elasticity phantom with a convex 4C1 probe and a linear 9L4 probe. The experimental setup was expanded by the use of an interposed piece of porcine muscle as standoff material. The probe pressure on the phantom was registered. RESULTS: Faulty ARFI measurements occurred more often when quantifying the hardest lesion (74.0 kPa 4.97 m/sec) by the 9L4 probe with the porcine muscle as a standoff material interposed between the probe and the phantom. The success rate for ARFI measurements in these series was 52.4%, compared with 99.5% in the other series. The SWV values measured with the 9L4 probe were significantly higher (3.33±1.39 m/sec vs. 2.60±0.74 m/sec, P < 0.001 in the group without muscle) and were closer to the reference value than those measured with the 4C1 probe (0.25±0.23 m/sec vs. 0.85±1.21 m/sec, P < 0.001 in the same group). The SWV values measured when using the muscle as a standoff material were lower than those without the muscle (significant for 9L4, P=0.040). The deviation from the reference value and the variance increased significantly with the 9L4 probe if the muscle was in situ (B=0.27, P=0.004 and B=0.32, P < 0.001). In our study, the pressure exerted by the operator had no effect on the SWV values. CONCLUSION: The presence of porcine muscle acting as a standoff material influenced the occurrence of failed measurements as well as the variance and the accuracy of the measured values. The linear high-frequency probe was particularly affected.
Acoustics* ; Elasticity ; Elasticity Imaging Techniques* ; Muscles ; Reference Values ; Transducers ; Ultrasonography

PURPOSE: The purpose of this study was to evaluate how the anisotropy and the static stretch stress of the cervical musculature influence the measured shear modulus in a tissue-mimicking phantom and in cervical lymph nodes in vivo by using shear wave elastography (SWE). METHODS: SWE was performed on a phantom using a pig muscle and on the middle jugular cervical lymph nodes in six volunteers. Tissue elasticity was quantified using the shear modulus and a supersonic shear wave imaging technique. For the phantom study, first, the optimal depth for measurement was determined, and then, SWE was performed in parallel and perpendicular to the muscle fiber orientation with and without strain stress. For the in vivo study, SWE was performed on the cervical lymph nodes in parallel and perpendicular to the sternocleidomastoid muscle fiber direction with and without neck stretching. The mean values of the shear modulus (meanSM) were then analyzed. RESULTS: In the phantom study, the measured depth significantly influenced the meanSM with a sharp decrease at the depth of 1.5 cm (P<0.001). Strain stress increased the meanSM, irrespective of the muscle fiber orientation (P<0.001). In the in vivo study, the meanSM values obtained in parallel to the muscle fiber orientation were greater than those obtained perpendicular to the fiber orientation, irrespective of the stretch stress (P<0.001). However, meanSM was affected significantly by the stretch stress parallel to the muscle fiber orientation (P<0.001). CONCLUSION: The anisotropic nature of the cervical musculature and the applied stretch stress explain the variability of the SWE measurements and should be identified before applying SWE for the interpretation of the measured shear modulus values.
Anisotropy* ; Elasticity ; Elasticity Imaging Techniques* ; Lymph Nodes* ; Neck* ; Ultrasonography* ; Volunteers

The aim of this study was to evaluate the change of supraspinatus muscle and tendon as well as biceps tendon after pitching in Korean professional baseball league pitchers by the application of sonoelastography. A total of 10 pitchers from Korean professional league were evaluated their supraspinatus muscle and tendon and long head of biceps tendon of dominant arm by sonoelastography at all-star break period. After one month later, re-evaluations were performed after pitching in the game. The strain ratio of supraspinatus muscle and tendon (red portion, soft; blue portion, hard), thickness of supraspinatus and long head of biceps tendons were evaluated. For the correlation analysis with pitching, numbers of pitches, maximal velocity, maximal difference of velocity and ratio of breaking balls among pitches were investigated. The strain ratios of supraspinatus muscle, thickness of supraspinatus and long head of biceps tendon were decreased but not statistically significant. However, the strain ratio of red portion in supraspinatus tendon was significantly increased. There were no correlations between sonoelastograpic findings and pitches.
Arm ; Baseball* ; Elasticity Imaging Techniques* ; Head* ; Tendons*

No abstract available.
Elasticity Imaging Techniques* ; Liver Cirrhosis* ; Liver*

No abstract available.
Elasticity Imaging Techniques* ; Fibrosis ; Hypertension, Portal*